Carcinogenic Polycyclic Aromatic Hydrocarbons Research Articles

Polycyclic Aromatic Hydrocarbons and Some of Organochlorine Pesticide Residues and Health Risk Assessments in Commonly Consumed Teas in Jordan

During the year 2020, 60 samples of black and green tea bags were collected from Jordanian markets. The samples were subjected to multi-residue analysis for 16 carcinogenic polycyclic aromatic hydrocarbons (PAHs) which belong to the Environmental Protection Agency (EPA) priority pollutant list and 20 banned organochlorine pesticides (OCPs). A QuEChERs method was developed for the determination of 16 EPA PAHs and OCPs residues using hyphenated gas chromatography–mass spectrometry (GC–MS) for analysis. To minimize the colors of chlorophyll and carotenoids, the concentrated extracts were subjected to 10 mg of activated charcoal for further extraction. The QuEChERs technique has been validated, and the outcomes in terms of linearity, detection limits, quantitation limits, precision, and recovery have been satisfactory. On one hand, none of the examined black and green tea bag samples contained any of the studied OCPs, while the estimated quantities of PAHs, on the other hand, ranged from 280.03 to 486.46 µg kg−1, and the amounts of benzo[a]pyrene ranged from 4.85 to 8.56 µg kg−1. The light PAHs were predominant in both black and green tea samples (90%), while the contribution of heavy PAHs was much less significant (10%). The incremental lifetime cancer risk (ILCR) was evaluated, and the values for all tea samples have not exceeded the limit value of 10−6 but ranged from 4.17 × 10−8 to 0.0158 × 10−8, thus indicating a slight potential risk.

Reusable Cavitand-Based Electrospun Membranes for the Removal of Polycyclic Aromatic Hydrocarbons from Water.

The removal of toxic and carcinogenic polycyclic aromatic hydrocarbons (PAHs) from water is one of the most intractable environmental problems nowadays, because of their resistance to remediation. This work introduces a highly efficient, regenerable membrane for the removal of PAHs from water, featuring excellent filter performance and pH-driven release, thanks to the integration of a cavitand receptor in electrospun polyacrylonitrile (PAN) fibers. The role of the cavitand receptor is to act as molecular gripper for the uptake/release of PAHs. To this purpose, the deep cavity cavitand BenzoQxCav is designed and synthetized and its molecular structure is elucidated via X-Ray diffraction. The removal efficiency of the new adsorbent material toward the 16 priority PAHs is demonstrated via GC-MS analyses at ng L-1 concentration. A removal efficiency in the 32%, to 99% range is obtained. The regeneration of the membrane is performed by exploiting the pH-driven conformational switching of the cavitand between the vase form, where the PAHs uptake takes place, to the kite one, where the PAHs release occurs. The absorbance and regeneration capability of the membrane are successfully tested in four uptake/release cycles and the morphological stability.

Source identification and health risk assessments of polycyclic aromatic hydrocarbons in settled dusts from different population density areas of Ilorin, Nigeria.

Polycyclic aromatic hydrocarbons (PAHs) have attracted significant attention in recent times on account of their reasonably high environmental burden and extreme toxicity. Samples of indoor dusts were obtained daily over a period of 2weeks from 10 residences located within low, medium, and high density residential areas of Ilorin City. The concentration levels, potential sources, and cancer health risks of sixteen polycyclic aromatic hydrocarbons (PAHs) were investigated using gas chromatography/mass spectrometry. PAHs total concentrations varied from 3.95 ± 0.19 to 8.70 ± 0.43μg/g with arithmetic mean of 6.09 ± 0.46μg/g. Fluoranthene was the most dominant PAHs congener. High molecular weight (HMW) PAHs (4-6 rings) were the most prevalent PAHs and were responsible for 79.29% of total PAHs in sampled residences. Chrysene (Chry) was the most abundant compound among the 7 carcinogenic PAHs (CPAHs). Moreover, diagnostic ratios and positive matrix factorization (PMF) employed to apportion PAHs suggested that indoor dusts originated from indoor activities and infiltrating outdoor air pollutants. Diagnostic ratios revealed that PAHs are from mixed sources which include coal/wood combustion, non-traffic and traffic emissions, petroleum, petrogenic (gasoline), and petroleum combustion. Similarly, positive matrix factorization (PMF) model suggested five sources (factors) were responsible for PAHs in indoor dusts comprised of petroleum combustion and traffic emissions (60.05%), wood and biomass combustion emissions (20.84%), smoke from cooking, incense burning and tobacco (4.17%), gasoline combustion from non-traffic sources (13.89%), and emissions from coal burning and electronic devices (1.05%). The incremental lifetime carcinogenic risks (ILCR) of PAHs in adults and children estimated by applying benzo(a)pyrene (BaP) equivalent were within the satisfactory risk limits in Ilorin. Indoor PAHs emissions in Ilorin residences could be monitored and controlled by using data provided in this study.

Occurrence of polycyclic aromatic hydrocarbons (PAHs) carcinogen in Indonesian commercial goat satay

This study aimed to investigate the carcinogen content of polycyclic aromatic hydrocarbons (PAHs) in commercial charcoal grilled goat satay. Twenty-one portions of commercial raw goat satay and charcoal grilled goat satay samples were obtained from 4 restaurants which are the largest, well-known, and 15-55 years old goat satay restaurant in Batu Municipality, East Java. Sampling of 2 goat satay types (goat satay without sliced fat and goat satay with sliced fat) was carried out 3 replications in 3 consecutive weekends where many tourists visited. The results showed that the temperature of wood charcoal for grilling commercial raw goat satay in various satay restaurants ranged 486.833-548.300 oC with a grilling duration of 2-5.5 minutes and grilling distance of 0.5-2 cm. The weight of raw goat satay for a serving (10 skewers) ranged 144.000-194.000 g and after grilling the weight ranged 97.333-148.000 g. Total natural antioxidant activity (Dipheny-picrylhydrazyl, DPPH), fat content and moisture content of raw goat satay with sliced fat and without sliced fat reached up to 36.661 and 34.124%; 13.440-26.100% and 1.5-6.305%; 57.940-66.385% and 71.530-76.810%, respectively. Benzo(a)pyrene (BaP), the only type of PAHs that is carcinogenic, for charcoal grilled goat satay with sliced fat and without sliced fat in various satay restaurants, ranged from not detected to 6.330 mg/kg and not detected to 0.773 mg/kg, respectively. The levels of BaP in charcoal grilled goat satay in several satay restaurants exceeded the safety limit by National Agency of Drug and Food Control (NA-DFC) of Republic Indonesia. Benzo(a)antharacene (BaA) and pyrene (Pyr) were detected in all grilled goat satay samples in various satay restaurants. Whereas, phenanthrene (Phe), acenaphthene (Acp) and naphthalene (Nap) were not detected in all grilled goat satay samples in various satay restaurants. The conclusion of our study was that the commercial charcoal grilled goat satay that are sold in Batu municipality contains PAH, especially the carcinogenic B(a)P. Therefore practical mitigation efforts are needed for producers to reduce and prevent the formation of carcinogenic B(a)P in commercial charcoal grilled goat satay.

Pollution investigation and risk assessment of polycyclic aromatic hydrocarbons in soil and water from selected dumpsite locations in rivers and Bayelsa State, Nigeria.

The transfer ratio of polycyclic aromatic hydrocarbons (PAHs) from soil dumpsite to borehole water is dependent of polluting source and exposure matrices that causes immerse health risk to man and environment over a period of time. PAHs were assessed in selected soil dumpsite and borehole water located at Rivers state (Eleme, Eliozu, Eneka, Oyigbo, and Woji) and Bayelsa state (Yenagoa), Nigeria. Soil samples were collected at four different points 30 m (North, South, East and West) locations at a depth of 15 cm for each dumpsite using soil auger while control samples were collected 200 m away (farmland), where there were little anthropogenic activities and no presence of active dumpsites. Borehole water samples were collected from 300 m distance, which were packaged in an amber container, labeled, and transported to the laboratory for analysis. Standard analytical methods were employed. PAHs concentrations were analyzed using gas chromatography-mass spectrometry (GC-MS) after extraction of water and soil using liquid-liquid and soxhlet extraction methods respectively and clean-up of the extracts, thereafter the laboratory data generated were subjected to statistical analysis. Total PAHs (∑PAHS) concentrations in soil samples from the study sites ranged from 2.4294 mg/kg in Yenagoa to 5.1662 mg/kg in Eleme while in water samples the total PAHs ranged from 1.3935 mg/L in Woji to 3.009 mg/L in Eleme. The total PAH concentrations in the soil were above the Agency for Toxic Substances and Disease Registry levels of 1.0 mg/kg for a considerably contaminated site except for the control sites. The total concentration of carcinogenic PAHs ranged from 0.0038 to 1.1301mg/kg in soil samples and 0.0014 to 0.9429 mg/L in borehole water samples, therefore raising concern of human exposure via food chain. The results indicate that low molecular weight PAHs were more dominant than high molecular weight PAHs in both soil and water samples, however molecular diagnostic ratio shows that pyrogenic activities are major sources of PAHs as compared to petrogenic origin. Multivariate analysis (principal component analysis and Pearson correlation) showed strong negative correlation implying that they were from dissimilar sources and different migratory route. Cancer and non-cancer risk showed that children were more at risk compared to adults, where inhalation exposure were major contribution as compared to ingestion and dermal exposure, as such there is a need to implement regulatory laws on indiscriminate release of PAHs contaminants to maintain sustainability.

Measurement of soot mass and PAHs during the pyrolysis of C2[sbnd]C4 alcohols at high temperatures

Particulate matter (PM) is emitted from a range of combustion sources, can vary greatly in properties, and is able to penetrate deep into the human lungs, conveying carcinogenic PAHs present on the particle surface. Alcohol based biofuels have been shown to potentially reduce PM emissions when displacing fossil fuels. To improve understanding of the influence of fuel bound oxygen on and the relative toxicity of PM, this paper investigates quantitatively the soot mass and PAHs produced from the pyrolysis of ethanol, 1-propanol, 2-propanol,1-butanol, and 2-butanol in a laminar flow reactor. The pyrolysis of alcohol fuels and collection of soot-bound and gas-phase PAH was carried out between 1323 and 1623 K at a fixed carbon atom concentration in nitrogen. Accelerated solvent extraction (ASE) was used to extract soot bound PAH and gaseous species captured on XAD resin, with speciation and quantification of PAHs undertaken using GCMS. Of the primary alcohols, the highest and lowest masses of soot were observed for 1-butanol and ethanol respectively, while secondary alcohols generated more soot mass than corresponding primary alcohols. An effect of hydroxyl group position on the total PAH distribution in the gas and particulate-bound phases was observed within the temperature range of 1323 to 1423 K. At 1323 K, 1-propanol produced approximately three times more particle phase (PP) PAH concentration than 2-propanol. Amongst the fuels tested, 1-propanol produced the highest level of carcinogenic PAHs at 1323 K, while for all C3 and C4 fuels the toxicity equivalence factor decreased with increasing pyrolysis temperature.

Greener Monolithic Solid Phase Extraction Biosorbent Based on Calcium Cross-Linked Starch Cryogel Composite Graphene Oxide Nanoparticles for Benzo(a)pyrene Analysis.

Benzo(a)pyrene (BaP) has been recognized as a marker for the detection of carcinogenic polycyclic aromatic hydrocarbons. In this work, a novel monolithic solid-phase extraction (SPE) sorbent based on graphene oxide nanoparticles (GO) in starch-based cryogel composite (GO-Cry) was successfully prepared for BaP analysis. Rice flour and tapioca starch (gel precursors) were gelatinized in limewater (cross-linker) under alkaline conditions before addition of GO (filler) that can increase the ability to extract BaP up to 2.6-fold. BaP analysis had a linear range of 10 to 1000 µgL−1 with good linearity (R2 = 0.9971) and high sensitivity (4.1 ± 0.1 a.u./(µgL−1)). The limit of detection and limit of quantification were 4.21 ± 0.06 and 14.04 ± 0.19 µgL−1, respectively, with excellent precision (0.17 to 2.45%RSD). The accuracy in terms of recovery from spiked samples was in the range of 84 to 110% with no significant difference to a C18 cartridge. GO-Cry can be reproducibly prepared with 2.8%RSD from 4 lots and can be reused at least 10 times, which not only helps reduce the analysis costs (~0.41USD per analysis), but also reduces the resultant waste to the environment.

Carcinogenic Content of PM10-Bound PAHs in University Classrooms and Outdoors at an Urban Location in Rome, Italy, during Winter Working and Not-Working Days

To assess the contribution of carcinogenic Polycyclic Aromatic Hydrocarbons (PAHs) in ambient air, EU Directive 2004/107/EC indicates to monitor relevant carcinogenic PAHs in PM10 fraction other than benzo(a)pyrene at a limited number of measurement sites. This indication refers to outdoor environments, and the environmental air quality being taken as a reference also for indoors, it can be extended to indoor environments. In this work, the contribution of carcinogenic PAHs bound to PM10 has been evaluated in winter in two classrooms of a University campus in Rome with the aim of studying the relationship with the outdoors and with working activity. PM10-boundPAHs were monitored over five different periods selected to distinguish Weekend from daytime and nighttime Weekdays, separated into two parts of the week. Data aggregated over Weekend and Weekdays allowed calculating of the concentration of carcinogenic PAHs, the mass contribution to PM10, the Infiltration Factor, the indoor to outdoor Ratio, and the Total Carcinogenic Potency by Toxicity Equivalent Factors, for “not-working” and “working” days. In addition, some indications on contributions to the source have been obtained from the chemical profile normalized to the maximum value of concentration, which also provides the source fingerprint compound. Indoor PAH concentrations were lower than outdoor, and both accumulated as the week progressed. Although the two indoor environments were on the same floor and had a similar volume, they presented different contribution to PM10 and infiltration capacity, both higher during Weekend than on Weekdays. The analysis of indoor and outdoor chemical profiles normalized to the maximum concentration indicated an external source infiltrating the indoors environment. During Weekdays, the indoor fingerprint compound changed compared to that observed during Weekend, probably due to an additional contribution of local “fresh-traffic” source. The calculation of Total Carcinogenic Potency gave indoor values always lower than outdoor, confirming in the two classrooms different dynamics for carcinogenic PAHs. Moreover, the Total Carcinogenic Potency on Weekdays was twice that of Weekend, meaning a higher toxicological impact when urban “fresh-traffic” source is added. The present study shows that the dynamics of PM10-related carcinogenic PAHs can be different within adjacent classrooms of a building and during working and not-working days. This evidence suggests the possibility of a potential different impact on occupant exposure to be taken into account in planning monitoring programs of indoor pollution.

The effect of benzo[a]pyrene on the gut microbiota of Nile tilapia (Oreochromis niloticus).

Benzo[a]pyrene (BaP) is a highly toxic and carcinogenic polycyclic aromatic hydrocarbon (PAH) whose toxicological effects in the gut microbiota of aquatic organisms have not yet been fully revealed. Therefore, in this study, we used high-throughput 16S rRNA gene sequencing to evaluate the effects of BaP in the gut microbiome of Oreochromis niloticus, including its possible participation in the process of detoxification and its ability to recover. The fish were injected with a single intraperitoneal dose of 20mgkg-1 of BaP, and the effects in the microbiome were evaluated at 24, 72, and 120h post-injection. The results indicate a clear dysbiosis (in composition, relative abundance, diversity, and interaction networks) of the gut microbiota during 24h post-injection, dominated by Fusobacteria and Bacteroidetes and a decrease in Proteobacteria and Spirochaetae. Interestingly, a slight recovery of the microbiome begins at 72h and stabilises at 120h post-injection. Pathway analysis revealed the participation of the gut microbiome in PAH degradation mainly at 24h post-injection. This study provides new insights in the toxicology of BaP in O. niloticus and the first evidence of the ability of the gut microbiome to recovery after a chemical disturbance. KEY POINTS: • Benzo[a]pyrene caused a dysbiosis in the gut microbiota of Oreochromis niloticus. • We observed an enrichment of bacteria involved in the metabolism of xenobiotics. • The gut microbiota was recovered after exposure to benzo[a]pyrene.

Simultaneous analysis of PAH urinary mono- and dihydroxylated metabolites by GC-MS-MS following SPE and two-stage derivatization

A new gas chromatography-tandem mass spectrometry method for the determination of mono- and dihydroxylated polycyclic aromatic hydrocarbon metabolites (OH-PAHs and diol-PAHs) in urine was developed and validated. Various sample preparation procedures were compared, namely liquid-liquid extraction (LLE), dispersive solid-phase extraction (dSPE), and SPE, alone or combined. A novel two-stage derivatization approach using 2 silylation reagents was developed, and an experimental procedure design was used to optimize the programmed temperature vaporization-solvent vent injection (PTV-SV) GC parameters. The method focused on 11 target compounds resulting from four- to five-ring suspected carcinogenic PAHs. SPE was identified as an acceptable and more convenient extraction method for all tested metabolites, with extraction rates ranging from 63 to 86% and relative standard deviations lower than 20%. The two-stage derivatization approach successfully allowed first the derivatization of OH-PAHs by MTBSTFA (N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide) and then diol-PAHs by BSTFA (N,O-bis(trimethylsilyl)trifluoroacetamide) in a single run. The limits of quantification were in the range of 0.01-0.02μgl-1 for OH-PAHs and 0.02-0.2μgl-1 for diol-PAHs. The intra- and interday precisions were lower than 10%. The method was applied to determine PAH metabolites in urine collected at the beginning and at the end of the working week from 6 workers involved in aluminum production. The mean diol-PAH levels at the end of the week were 10 to 20 times higher (0.86-2.34μgg-1 creatinine) than those of OH-PAHs (0.03-0.30μgg-1). These results confirmed the usefulness of this new analytical technique for detecting and characterizing metabolic patterns of PAHs in urine and assessing carcinogenic occupational exposures.

Foliar Uptake and Accumulation of Polycyclic Aromatic Hydrocarbons from Diesel Emissions

Air pollution in settlements has become a continuously growing problem. Traffic, especially emission of diesel-powered vehicles, poses an important health risk. Emitted particles carry a wide range to potentially toxic chemicals, of them polycyclic aromatic hydrocarbons (PAHs) are the most important group of concern. Despite the risk of air pollution, rural gardens are very popular both for food production and for environmental benefit. On the other hand, several mutagenic and/or carcinogenic PAHs have been detected in leafy vegetables grown in impacted areas. In our study, the No. 227 OECD GUIDELINE FOR THE TESTING OF CHEMICALS: Terrestrial Plant Test: Vegetative Vigor Test was followed to assess foliar uptake of PAHs from aqueous extract of diesel aerosol sample. Significant differences were found in the bioaccumulation capacity of the tested vegetables as well as in their bioaccumulation pattern. In general, most vegetables showed good even strong correlation with individual PAHs of the diesel extract. In consistency with other studies, prevalence of 3- and 4-ring PAHs was experienced.

Distribution Trends and Source Diagnosis of Polycyclic Aromatic Hydrocarbons (PAHs) in Sediments of Imiringi River

The environmental menace caused by hydrocarbon releasing activities on water bodies have remained a cause for great concern. Such activities are accompanied by the release of highly toxic and carcinogenic polycyclic aromatic hydrocarbons (PAH), which are easily biomagnified across the food chain, ultimately aggravating adverse health conditions in human. This study was aimed at identifying the most important environmental contributors of PAHs in sediments of the Imiringi river. Owing to the activities of oil facilities among other anthropogenic influences, water bodies are inundated with hydrocarbon pollutants which settle within river bed sediments, thereby, playing an important role in the redistribution of contaminants. The applied diagnostic ratios (Phenanthrene/Anthracene, Fluorene/Fluorene + Pyrene, Fluoranthene/Fluoranthene + Pyrene, pyrogenic index and total index) revealed the presence of mixed source of PAHs (pyrogenic and petrogenic). PAH concentrations ranged from <0.01 to 3,965.4 µg/kg with most detected compounds exceeding regulatory limits. The high molecular mass PAHs (4 - 6 ring HPAHs) represents the primary source showing 94.29% distribution, while the low molecular mass PAHs (2 - 3 ring LPAHs) recorded trace concentrations of about 5.71% of total PAHs. Principal component analysis (PCA) revealed Indeno(1,2,3-cd)pyrene and Dibenz(a,h)anthracene as principal PAH components in the environment. In addition, Pearson correlation showed Benzo(k)fluoranthene and Benzo(b)fluoranthene as the most positively correlating PAH species in sediment. Overall, the midstream section of the river was relatively more polluted than the up and down-river locations. Most notably, HPAHs recorded higher concentrations than the LPAHs. This may be due to intensive agricultural practices such as bush incineration, while waste dumps along the river bank remain tangible pyrogenic PAH contributors. On the other hand, trace amounts of observed petrogenic PAHs in some locations are possibly spill-over’s from oil bunkering activities and infiltrations from nearby oil installations.

Insilico Insight into the Association between Polycyclic Aromatic Hydrocarbons and Human Toll like Receptor in Progression of Esophageal Carcinogenesis

Cancer creates enormous burden and is a leading cause of death in most of the countries. Esophageal cancer (EC) is one of the most common cancers in the world and has the worst survival of all cancers. Esophageal Squamous Cell Carcinoma (ESCC) and adenocarcinoma are the two main types of esophageal cancer. Exposure of polycyclic aromatic hydrocarbons (PAHs) can be cited as one of the reasons for development of Esophageal Squamous Cell Carcinoma. Toll Like Receptors (TLRs) present in human esophageal epithelial cells may pose a major role in pathogen recognition, activation of innate immunity and cancer. The study attempts to predict the role of carcinogenic PAHs in TLR4 signaling pathway and how it can ultimately result in immuno suppression and development of esophageal cancer by insilico docking evaluation. For the study we retrieved the structure of sixteen PAHs from the PubChem database and the protein model of TLR4 (PDB ID: 4G8A) from protein data bank (PDB). The binding affinity of PAHs to the TLR4 receptor was calculated using molecular docking software Auto Dock1.5. The results showed that Benzo[a]pyrene showed strong interaction toward TLR4 receptor with the highest number of polar contacts along with high binding affinity values. Considering the presence of Benzo[a] pyrene in different environmental, occupational and behavioral sources globally, there is a need for future research on the risk assessment of Benzo[a]pyrene on Esophageal Squamous Cell Carcinoma.

Irrigation with Coal Mining Effluents: Sustainability and Water Quality Considerations (São Pedro da Cova, North Portugal)

Two water effluents that drain from the abandoned coal mine of São Pedro da Cova (NW Portugal) were characterized in terms of their physic-chemical properties and suitability for irrigation purposes. Samples were also collected in a local surface stream, upstream and downstream from the mine drainage points, also used for irrigation by local farmers. Water samples were analyzed for major and minor ions and for trace element concentrations. Sampling campaigns started in 2017 and ended in 2019 and there were 46 water quality parameters tested. There were also proposed all-inclusive indices (the Water Quality Index and the Contamination Index, and also the Trace Element Toxicity Index) based on specific groups of 18 and 17 physic-chemical parameters, respectively, to achieve adequate monitoring requirements for mine effluents and surface water from coalfield. From the physical and chemical aspects of mine water it is inferred that the mine is not producing acid mine drainage. The coal mine water is of medium to high salinity, having almost neutral pH and a high thermal stability during the year, which is a distinguishing feature of the effluents. When compared to international irrigation water quality standards, as Food and Agriculture Organization of the United Nations admissible concentrations, the impacted waters are unsuitable for irrigation. The major outliers to the guidelines were iron, manganese, potassium, magnesium and bicarbonates, being also detected carcinogenic polycyclic aromatic hydrocarbons. Cost-effective ways of monitoring water quality parameters are needed to help control and manage the impact of coal mine effluents that should be treated before releasing into a ditch system that could be then used by local farmers to irrigate their crops.

Distribution of Polycyclic Aromatic Hydrocarbons in Surface Water and Fishes in Bodo/Bonny River Nigeria

Several industrial activities around the Niger Delta region have contributed to the widespread contamination of marine ecosystems with organochlorine compounds (OCs), petroleum products that are a source of polycyclic aromatic hydrocarbons (PAHs). These pollutants tend to be persistent in the environment and are also often highly toxic to the biota. The study was therefore, aimed at determining the concentrations of organic pollutants (PAHS) in the Bodo/Bonny coastal waters and their effect on the marine ecosystems. This is exacerbated by the risks posed by polycyclic aromatic hydrocarbons (PAHs) in oil spilled environments. Surface water, sediment and fish samples were collected from different sampling stations along the river and analyzed using standard analytical methods. Sampling of surface water was done on Link fish pond which served as control. The results of the value of TPH ranged from 0.31 to 40.85 mg/l, PAHs range from 2.06 to 2.73 mg/l and BTEX ranged from 0.043 to 0.081 mg/l. The Total Petroleum hydrocarbon (TPH) values obtained were above DPR permissible Limit of 20 mg/l in all the stations. However, values of individual polycyclic aromatic hydrocarbons show that Benzo(a) anthracene had the highest concentration especially in all the surface water stations sampled. Also results showed a presence of carcinogenic PAHs in the fish tissues. This still poses a danger if accumulation was to take place over a long period of time. The values obtained from this study stations also exceeded the WHO quality criteria for drinking, aquatic life support and recreation. This reveals that Bodo/Bonny River is under pollution threat and underscore the need for early remediation if adverse health defects are to be prevented.

The role of melatonin hormone and its receptor (type1A) as anti-cancer against carcinogenic effect of polyaromatic hydrocarbons in Iraqi refinery workers

Air pollution is a global health threat and causes millions of human deaths annually. Outdoor and indoor air pollutants such as polycyclic aromatic hydrocarbons (PAHs) are the most prevalent cause of respiratory disorders, lung disease, pregnancy disorders, endocrine disturbances, diabetes, obesity, cardiovascular disease and cancer because pollutants can alter gene expression via epigenetics like DNA methylation and histone modifications which can initiate tumorigenesis and progressed to cancer. Carcinogenicity of PAHs can be eliminated by endogenous melatonin hormone (MT) via binding to its receptor (MTNR1A) that act as free radicals scavenger therefore it protects the body from developing occupational cancer. Aims of studyTo predict the protective effect of melatonin hormone as anti-cancer through binding to its receptor (MTNR1A) against any type of cancer that can be induced by chronic exposure to air pollutants. Subjects and methodsThis study includes 168 participants, they have been divided into three groups (control, refinery field workers and refinery office workers). PAH was analyzed for each participant by GC/MS whereas melatonin hormone and MTNR1A were measured by ELISA technique. ResultsPAHs were absent in the blood of control, and they were elevated in refinery worker’s specimens. Concentration of MT was higher in field worker than in office and control group as well as MTNR1A, also there is a relation between their levels and duration of exposure. ConclusionExposure to PAHs can lead to oxidative stress that can damage DNA resulting in many types of cancer but this carcinogenic effects of PAHs can be eliminated by natural endogenous biomolecules such as MT and its receptor (MTNR1A) therefore their elevation has a beneficial effect as anti-cancer to reduce the oxidative stress and prevent tumorigenesis.

Environmental impact and human health risk assessment of polycyclic aromatic hydrocarbons (pahs) in raw milk from free-ranging cattles in northwest nigeria.

Polycyclic aromatic hydrocarbons (PAHs) were determined in raw milk from Northwest Nigerian cattle (cow, goat and sheep) as indicators in assessing the current pollution status of the region. In Northwest Nigeria, most animals are free rangers with the likelihood that PAHs have been taken up by these animals on the process of drinking PAHs contaminated surface waters, eating road-side grasses, and soils. A total of 42 composite milk samples were collected by milking 3-5 animals. PAHs were extracted after saponification of the milk fats through sonication using dichloromethane/hexane mixture and the five ascertained most abundant PAHs are: Phe > BaP > Chr > Fla. > Pyr using gas chromatography-flame ionization detector (GC-FID). The diagnostic ratios showed that combustion is the major pathway of PAHs emission in the study area which judging from the economic level of the area, could be attributed to vehicular exhaust emission, use of firewood, industrial fumes, waste incineration and bush burning at the beginning of the farming season. The values of PAHs showed no significant variations (p > 0.05), either between the milk types (cow, goat and sheep) or between the seven states' milk samples, indicating a similar source of the PAHs. The European Food Safety Authority set 2μg/kg w/w BaP as a marker for the occurrence of PAHs contamination and assessment of likely effect of carcinogenic PAH in foodstuffs, the value of BaP obtained was however much higher even though raw milk is about 80% water. Most PAHs have carcinogenic effects on humans and induce various cancers. Therefore there should be a reduction in the bush burning at the beginning of the farming season, use of firewood and other pronounced sources of PAHs in the region.

Source apportionment and risk assessment for polycyclic aromatic hydrocarbons in soils at a typical coking plant

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment. The coking industry is an important industrial source of PAHs. Coke production in China accounts for 67.44% of total global coke production. Tangshan, a coastal city on the Bohai Rim, contains the largest cluster of coking plants in China. Extremely high PAH emissions in Tangshan may cause long-distance cross-border pollution problems. In this study, the concentrations and sources of 16 priority PAHs in soil at a coking plant in Tangshan were determined and the risks posed by the PAHs were assessed. The PAH concentrations were generally higher in surface soil than subsurface soil, particularly near the coke oven, crude benzol, and coal blending areas. The dibenz[a,h]anthracene (DBA) concentrations were higher than the risk screening value (1500 ngg−1) but lower than the control value (15,000 ngg−1) for type II land defined in Chinese standard (GB36600-2018). The main sources of PAHs were coal combustion, the coke oven, and traffic. The PAH concentrations were higher in the ammonium sulfate, boiler room, coal blending, and coke oven areas than in the other areas. Toxic equivalent concentrations were calculated to assess the toxic and carcinogenic risks posed by PAHs. The toxic equivalent concentrations were relatively high in the boiler, crude benzol, and coal blending areas, where the toxic equivalent concentrations for the sums of seven highly carcinogenic PAHs contributed 95% of the toxic equivalent concentrations for the sums of the 16 PAHs that were analyzed. The carcinogenic risks posed to humans were therefore assessed using the concentrations of the seven highly carcinogenic PAHs. Dermal contact was found to be an important exposure pathway leading to carcinogenic risks. The carcinogenic risk posed by DBA was > 1 × 10−6 but < 5 × 10−6, indicating that DBA concentrations at the study site monitored closely.

Occupational cancers in urology

Cancers can be triggered by occupational causes. In the field of urology, bladder cancer is by far the most frequent occupationally induced tumor disease. Causes are particularly carcinogenic aromatic amines and carcinogenic polycyclic aromatic hydrocarbons. The frequency of this disease has shifted over the last decades from the classical hazard in the chemical industry to the users. Among avariety of hazardous occupations, hairdressers and painters are the best known. Rarely, renal cell carcinoma can be triggered by high trichloroethylene exposure and mesothelioma of the tunica vaginalis testis by asbestos. If a disease that can be caused by occupational activities has been confirmed (e.g. urinary bladder cancer), the risk factors must be recorded by acomplete occupational history from the first employment on in order to be able to report asuspected occupational disease. In addition, spinal cord injury due to occupational and commuting accidents can lead to urinary bladder cancer over the long term.

Cancer Risk Levels for Sediment- and Soil-Bound Polycyclic Aromatic Hydrocarbons in Coastal Areas of South Korea

The increasing cancer risk (CR) due to sediment- and soil-bound polycyclic aromatic hydrocarbons (PAHs) is one of the major threats to public health. The CR of sediment- and soil-bound carcinogenic PAHs was estimated for the first time in coastal and residential areas near an industrial zone in Korea. Monte Carlo probabilistic simulations and sensitivity tests were conducted to calculate the CR and to identify the most sensitive parameters. The CR was found to be highest in the coastal areas of Korea. Ulsan, which is located on the southeastern coast of Korea, was classified as a high cancer risk zone according to United States Environmental Protection Agency standards, while the western coast and Mohang Harbor were classified as moderate cancer risk zones. Fish consumption was identified as the main contributor (94–99%) to the total risk levels in the coastal areas. The biota-to-sediment accumulation factor (43–76%) and PAH levels (8–44%) in sediment were identified as the parameters that were most sensitive to the CR. In the residential area, the CR was found to be within the range of 10–6–10–4, which categorized it as a low cancer risk zone. Furthermore, the CR for residents in the industrial area was estimated to be 12 and 5 times higher than that for residents in the rural and urban areas, respectively. The exposure duration (55–85%) and skin adherence factor for soil (35–42%) were identified as the most sensitive parameters for the overall CR in the residential area. Korea generally has high fish and seafood consumption, which has been recognized as the most significant exposure route for CR in the studied coastal areas. Thus, the consumption of fish and seafood from coastal areas, especially those near Ulsan, might be responsible for the increasing number of cancer patients in Korea.